/*
tip_followscroll.js        v. 1.1

The latest version is available at
http://www.walterzorn.com
or http://www.devira.com
or http://www.walterzorn.de

Initial author: Walter Zorn
Last modified: 21.6.2007

Extension for the tooltip library wz_tooltip.js.
Lets a "sticky" tooltip keep its position inside the clientarea if the window
is scrolled.
 */

//Here we define new global configuration variable(s) (as members of the
//predefined "config." class).
//From each of these config variables, wz_tooltip.js will automatically derive
//a command which can be passed to Tip() or TagToTip() in order to customize
//tooltips individually. These command names are just the config variable
//name(s) translated to uppercase,
//e.g. from config. FollowScroll a command FOLLOWSCROLL will automatically be
//created.
//===================        GLOBAL TOOPTIP CONFIGURATION        ======================//
config.FollowScroll = false
// true or false - set to true if you want this to be the default behaviour
// ======= END OF TOOLTIP CONFIG, DO NOT CHANGE ANYTHING BELOW ==============//

// Create a new tt_Extension object (make sure that the name of that object,
// here fscrl, is unique amongst the extensions available for
// wz_tooltips.js):
var fscrl = new tt_Extension();

// Implement extension eventhandlers on which our extension should react
fscrl.OnShow = function() {
    if (tt_aV[FOLLOWSCROLL]) {
        // Permit FOLLOWSCROLL only if the tooltip is sticky
        if (tt_aV[STICKY]) {
            var x = tt_x - tt_GetScrollX(), y = tt_y - tt_GetScrollY();

            if (tt_ie) {
                fscrl.MoveOnScrl.offX = x;
                fscrl.MoveOnScrl.offY = y;
                fscrl.AddRemEvtFncs(tt_AddEvtFnc);
            } else {
                tt_SetTipPos(x, y);
                tt_aElt[0].style.position = "fixed";
            }
            return true;
        }
        tt_aV[FOLLOWSCROLL] = false;
    }
    return false;
};
fscrl.OnHide = function() {
    if (tt_aV[FOLLOWSCROLL]) {
        if (tt_ie)
            fscrl.AddRemEvtFncs(tt_RemEvtFnc);
        else
            tt_aElt[0].style.position = "absolute";
    }
};
// Helper functions (encapsulate in the class to avoid conflicts with other
// extensions)
fscrl.MoveOnScrl = function() {
    tt_SetTipPos(fscrl.MoveOnScrl.offX + tt_GetScrollX(), fscrl.MoveOnScrl.offY
            + tt_GetScrollY());
};
fscrl.AddRemEvtFncs = function(PAddRem) {
    PAddRem(window, "resize", fscrl.MoveOnScrl);
    PAddRem(window, "scroll", fscrl.MoveOnScrl);
};
